This invention relates to a process for the production of vinegar by fermentation and to an apparatus for carrying out this process.
Today, the production of vinegar world-wide is mainly carried out by two processes, namely by a fermentation process similar to ancestral techniques, in which an alcoholic must trickles through a bed of wood chips, and by a more recent process known as submerged fermentation.
A detailed description of these two types of process can be found, for example, in Great Britian patent Specification No. 781,584 and Great Britian Patent Specification No. 1,101,560.
As can be seen from these two British patent specifications and as is confirmed, for example, by U.S. Pat. No. 4,282,257, problems are involved in obtaining high outputs of a vinegar of high acetic acid content. If a process is modified to increase output, the vinegar obtained has a lower acetic acid content and vice versa.
Thus, outputs of 0.2 to 0.3 g acetic acid per m.sup.3 fermenter per hour for a final acetic acid content of 12 to 13% may be considered as typical of a trickle-phase fermentation process. Compared with these figures, Great Britian Complete Patent Specification No. 781,584 illustrates a 5-fold increase in output, for example, although the vinegar obtained contains only 7.5 acetic
Similarly, the submerged fermentation process, which is more sophisticated and energy-intensive, typically enables a vinegar containing 12 to 13% acetic acid to be obtained with an output of 1 to 2 kg/m.sup.3.h. By comparison with these figures, U.S. Pat. No. 4,282,257 illustrates a final acetic acid content increased to 20%, for example, although this is achieved with an output of apparently less than 0.5 kg/m.sup.3.h.